Hista Block

Over 1/3 of all Americans (approximately 50 million people) are affected by allergies, according to a survey commissioned by the American College of Allergy, Asthma and Immunology (ACAAI). In addition, at-work productivity losses associated with the treatment of allergic rhinitis (commonly known as hayfever) have been estimated to cost the United States up to $4.6 billion annually. Interestingly, the most significant losses were the result, not of absenteeism, but of reduced at-work productivity associated with the use of sedating over-the-counter (OTC) antihistamines.1-4

Allergies are over-responsive (hypersensitive) reactions by the immune system to normally innocuous, commonly encountered substances such as pollen, molds and dust mites. White blood cells, particularly mast cells, release histamine and other inflammatory substances that cause changes in blood flow, coughing, mucus production, sneezing, narrowing of the bronchi (airways in the lungs), and watering eyes.3-9

Antihistamine medications are most often employed to treat common allergic symptoms brought on by histamine. Unfortunately, their side effects (which are often worse than the original allergy symptoms) can include drowsiness, weakness, slowed reaction time, and in some cases, dry mouth, upset stomach and bowel changes. In addition, a recent study found that people operating a driving-simulation machine performed worse after taking the popular antihistamine dephenhydramine than those given alcohol prior to the test. Furthermore, conventional medical allergy treatments are largely concerned with relieving symptoms and suppressing the allergic response. In contrast, naturopathic medicine strives to strengthen the body’s immune system to reduce its hypersensitivity, in addition to relieving symptoms.4,6,10

HistaBlock contains a powerful blend of herbs and nutrients that naturally enhance immune function and inhibit the release of histamine and other inflammatory compounds that initiate the sneezing, swelling and itching of allergic reactions. HistaBlock can be used to safely relieve allergy symptoms and improve breathing, without the side effects commonly associated with over-the-counter and prescription antihistamines, decongestants and nasal sprays.

Stinging nettle appears to be an effective anti-allergy herb for reducing congestion, coughs, runny noses, sneezing and other respiratory allergy symptoms. A double-blind clinical trial showed stinging nettle was rated moderately or highly effective in reducing allergic symptoms of allergic rhinitis in 58% of study participants, compared to only 37% taking a placebo. Stinging nettle is commonly used by naturopathic physicians and licensed acupuncturists as an ingredient in formulas for treating hayfever and other allergies. Stinging nettle is also reported to be helpful as an expectorant and has been used to treat bronchial and asthmatic conditions, coughs and tuberculosis. Stinging nettle is contraindicated in pregnant and breast-feeding women because of its diuretic and uterine-stimulant properties, and is also contraindicated in children under age 2.11-16

Quercetin is a flavonoid found in apples, onions and black tea that possesses anti-allergenic, antihistaminic and anti-inflammatory activity. Quercetin exhibits significant anti-inflammatory activity by directly inhibiting both the production and release of histamine and other allergic-related compounds. In fact, a study conducted by researchers in Japan shows that quercetin reduced histamine release by as much as 96%. Quercetin’s membrane stabilizing action (which helps prevent mast cell release of histamine) is likely to be responsible for some of its anti-inflammatory activity. Quercetin has also been shown to significantly reduce leukotriene formation. Leukotriene is an inflammatory compound that causes bronchoconstriction—excessive leukotriene formation has been linked to asthma. In addition, quercetin exerts powerful antioxidant activity and a vitamin C-sparing effect, enabling vitamin C to work longer. Furthermore, quercetin possesses the greatest antiviral activity of all flavonoids against respiratory syncytial virus, known to cause minor respiratory infections in adults and bronchitis and bronchopneumonia in children.5,7,8,17-19

The use of quercetin with bromelain may provide additional anti-inflammatory benefit, since combining protein-digesting enzymes (like bromelain) and flavonoids has been shown to enhance each other’s anti-inflammatory activity.5

Bromelain, a proteolytic (protein-digesting) enzyme from pineapples, has demonstrated good results in the treatment of upper respiratory tract infections. For example, bromelain produced good to excellent results in 87% of patients with acute sinusitis. In a combined study of both acute and chronic sinusitis, bromelain caused marked improvement, effectively thinning nasal secretions, decreasing inflammation and swelling of the nasal mucosa, and reducing headaches. In the treatment of chronic bronchitis, bromelain provided an antitussive (suppressing cough) action and reduced the viscosity (thickness) of sputum—matter composed of saliva mixed with mucus or pus that is coughed up from the lungs and respiratory passages. Bromelain also reduces epinephrine-induced pulmonary swelling (swellings of the lungs) and improves pharyngitis and throat infections. In addition, bromelain has been found to increase lung capacity and function, most likely due to bromelain’s anti-inflammatory and mucolytic (breaking down of mucus by an enzyme) actions. In other words, bromelain reduces inflammation and swelling of respiratory tract tissues and decreases both the thickness and volume of respiratory mucus, making breathing easier. Bromelain also enhances immune function, in part, by breaking down the protective membranes of antigens (foreign substances such as bacteria or toxins), which enables immune cells to better identify and destroy them. Bromelain has even been shown in clinical studies to be as effective as antibiotics in treating bronchitis and pneumonia. It is important to note that clinical studies indicate bromelain increases absorption of various antibiotics, including amoxycillin, chloramphenicol, erythromycin, penicillin and tetracycline, and thus, may enhance their effectiveness.5,20-23

Fructus aurantia, also known as bitter orange, is commonly used in traditional Chinese medicine as an expectorant for eliminating excess phlegm and relieving congestion. Research indicates that Fructus aurantia contains the flavone nobiletin, a potent antioxidant that exhibits anti-allergic, antihistaminic and anti-inflammatory actions. In addition, Fructus aurantia contains the active ingredient synephrine, whose properties include decongestant effects on the respiratory system, as well as alpha-adrenergic agonist activity (which blocks responses of alpha-adrenergic receptors to norepinephrine—a hormone and neurotransmitter that constricts blood vessels and increases heart rate and blood pressure). By blocking this response, synephrine helps reduce the smooth muscle tone of peripheral blood vessels, which in turn, increases peripheral circulation and decreases blood pressure. In simpler terms, synephrine helps maintain normal blood pressure levels, while simultaneously providing decongestant effects such as increasing circulation to the head, shrinking swollen tissues, and dilating respiratory passages to improve breathing. Such evidence helps support the use of Fructus aurantia in herbal nasal decongestants, and lends credence to its usefor allergies, asthma, coughs and symptoms associated with colds.14,24-33